Diane M. Harper, M.D., M.P.H., from the Helsinki University Hospital, and colleagues enrolled women aged 18 years and older who had confirmed CIN2/3 in a placebo-controlled phase II trial and randomly assigned them to either vaccine or placebo in a 2:1 ratio (129 and 63 patients, respectively). The primary end point was histologic resolution of CIN2/3 at excision performed at month 6. Cytology and high-risk HPV typing were performed through 30 months.

The researchers found that complete resolution of CIN2/3 was significantly higher in the vaccine group versus the placebo group (24 versus 10 percent; P < 0.05), regardless of the 13 high-risk HPV types assayed. The same findings were demonstrated for only CIN3 (21 versus 0 percent; P < 0.01), also regardless of high-risk HPV type. Viral DNA clearance was higher in the vaccine group versus the placebo group (P < 0.001), regardless of baseline HPV infection. The vaccine was well tolerated; injection site reactions were the most common adverse events.

"Immunologic therapeutic HPV vaccines offer a potential nonsurgical option for women with cervical precancers which might be extended to other HPV-associated precursors or cancers in the future," the authors write.

Several authors disclosed financial ties to pharmaceutical companies, including Roche, which funded the study and sold the compound to Transgene who facilitated data analysis.